On 2021-11-19 5:17 a.m., xinhui pan wrote:
amdgpu_amdkfd_gpuvm_free_memory_of_gpu drop dmabuf reference increased in
amdgpu_gem_prime_export.
amdgpu_bo_destroy drop dmabuf reference increased in
amdgpu_gem_prime_import.
OK. This was not obvious at all. The get_dma_buf in
amdgpu_gem_prime_import could use a comment that it's balanced by the
dma_buf_put in drm_prime_gem_destroy, which gets called from
amdgpu_bo_destroy for any bo that has a bo->tbo.base.import_attach.
I confirmed the bug and tested the fix by running the following test on
a 2-GPU system
HSA_USERPTR_FOR_PAGED_MEM=0 run_kfdtest.sh
--gtest_filter=KFDMemoryTest.MMBench
So remove this extra dma_buf_put to avoid double free.
Signed-off-by: xinhui pan <xinhui.pan@xxxxxxx>
Tested-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
Reviewed-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 6 ------
1 file changed, 6 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 6c6d5d994b5d..0f68d28e002e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -665,12 +665,6 @@ kfd_mem_attach_dmabuf(struct amdgpu_device *adev, struct kgd_mem *mem,
if (IS_ERR(gobj))
return PTR_ERR(gobj);
- /* Import takes an extra reference on the dmabuf. Drop it now to
- * avoid leaking it. We only need the one reference in
- * kgd_mem->dmabuf.
- */
- dma_buf_put(mem->dmabuf);
-
*bo = gem_to_amdgpu_bo(gobj);
(*bo)->flags |= AMDGPU_GEM_CREATE_PREEMPTIBLE;
(*bo)->parent = amdgpu_bo_ref(mem->bo);
